In general daily life, various lighting devices can be seen everywhere, such as fluorescent lamps, street lamps, table lamps, art lamps, and the like. In the above lighting apparatus, a tungsten filament bulb is conventionally used as a light source. In recent years, due to the rapid development of technology, light-emitting diodes (LEDs) have been used as sources of illumination. In addition, in addition to lighting equipment, for general traffic signs, billboards, lights, etc., also use LEDs as a light source. As mentioned above, the use of light-emitting diodes as light-emitting sources has the advantages of power saving and greater brightness, so it has gradually become common in use.
With the development of lighting technology, people are increasingly demanding light sources, such as the size of the spot, the direction of the light, and even the illuminance, chromaticity, and lumen value of the light. Especially in some wall washers, people are very eager to have spots of a specific shape, such as squares, such as rectangles. However, for some spotlights such as downlights, it is often difficult to achieve a square spot.